Diaphragm chuck

Abstract

A diaphragm chuck ( 1 ) with clamping jaws ( 3 ) inserted in its chuck body ( 2 ) in a driven connection with a diaphragm ( 4 ) that can be deformed by an axially adjustable actuator ( 5 ) and is provided with clamping jaws ( 3 ) with contact pieces ( 22 ), in which counterweights ( 8 ) assigned to the clamping jaws ( 3 ) are inserted into recesses ( 7 ) of the chuck body ( 2 ) and the clamping jaws ( 3 ) can be clamped against the diaphragm ( 4 ) by means of quick-clamping devices ( 31 ) engaging in the contact pieces. The contact pieces ( 22 ) are each provided with an intermediate element ( 101 ) in the area between the clamping jaws ( 3 ) and the quick-clamping devices ( 31 ) by means of which the flexural moments and/or rotational torques created by the quick-clamping device ( 31 ) can be eliminated and it is possible to transmit exclusively axially vectored tensile forces onto the clamping jaws ( 3 ). The effect of this embodiment is that the clamping jaws ( 3 ) are not unfavorably influenced by the moments created by the quick-clamping devices ( 31 ).

1. A diaphragm chuck ( 1 ) comprising clamping jaws ( 3 ) connected to a chuck body ( 2 ) and adapted to act on a workpiece ( 10 ) to be clamped, said jaws being in a driven connection with a diaphragm ( 4 ) that is located on a front face ( 11 ) of the chuck body ( 2 ), and being attached to an outer area of the chuck body ( 2 ) and deformable by means of a centrally arranged, axially adjustable actuator ( 5 ), the chuck further comprising counterweights ( 8 ) assigned to said clamping jaws ( 3 ) and located in recesses ( 7 ) in the chuck body ( 2 ), each of said clamping jaws ( 3 ) being designed as clamping heads ( 21 ) each equipped with an offset contact piece ( 22 ) axially arranged in the direction of the chuck body ( 2 ) and extending generally axially in parallel to the chuck body ( 2 ), the contact pieces ( 22 ) being held in recesses ( 20 ) in said counterweights ( 8 ) and said clamping jaws ( 3 ) being clamped against the diaphragm ( 4 ) and said counterweights ( 8 ) by means of quick-clamping devices ( 31 ,  71 ) that engage in the contact pieces ( 22 ) and act in an axial direction of the contact pieces ( 22 ), at least one of said clamping jaws ( 3 ) and the clamping heads ( 21 ) being directly supported against a first reference surface ( 23 ) running axially in parallel to the chuck body ( 2 ) in the clamping position, and against a second reference surface ( 24 ) of the diaphragm ( 4 ) at right angles to the first reference surface ( 23 ),
 wherein 
 the contact pieces ( 22 ) of said clamping jaws ( 3 ) and the clamping heads ( 21 ) are each equipped with an intermediate element ( 101 ;  111 ;  121 ;  131 ) in an area between said jaws ( 3 ) and the heads ( 21 ) on one hand and the quick-clamping devices ( 31 ,  71 ) on the other hand, by means of which intermediate element ( 101 ;  111 ;  121 ;  131 ) flexural moments and rotational torques of the quick-clamping devices ( 31 ,  71 ) are eliminated and exclusively axially vectored tensile forces are transmitted onto the selected one of said clamping jaws ( 3 ) and the clamping heads ( 21 ). 
 
     
     
       2. The diaphragm chuck in accordance with  claim 1 ,
 wherein 
 the intermediate element ( 101 ) is formed by a ball joint ( 102 ) arranged in an area of a subdivision of at least one of the contact pieces ( 22 ). 
 
     
     
       3. The diaphragm chuck in accordance with  claim 2 ,
 wherein 
 the ball joint ( 102 ) is formed by a coupling element ( 103 ) projecting from at least one of the contact pieces ( 22   a ) of the subdivided contact piece ( 22 ), the coupling element ( 103 ) being provided with a spherical outer jacket surface ( 104 ), and with a recess ( 105 ) in another part ( 22   b ) of the contact piece ( 22 ), the recess ( 105 ) having a corresponding contact surface ( 106 ) on the inner jacket surface facing the coupling element ( 103 ). 
 
     
     
       4. The diaphragm chuck in accordance with  claim 3 ,
 wherein 
 the coupling element ( 103 ) is acted on by a compression spring ( 107 ) that is supported against the part ( 22   b ) of the contact piece ( 22 ) that engages in the coupling element ( 103 ). 
 
     
     
       5. The diaphragm chuck in accordance with  claim 3 ,
 wherein 
 the coupling element ( 103 ) can rotate to a limited extent in the recess ( 105 ) of the part ( 22   b ) of the clamping piece ( 22 ) that accommodates the coupling element ( 103 ). 
 
     
     
       6. The diaphragm chuck in accordance with  claim 5 ,
 wherein 
 a pin ( 108 ) is disposed in the coupling element ( 103 ) to provided for secure rotation, the pin ( 108 ) being supported in a hole ( 109 ) in the part ( 22   b ) of the contact piece ( 22 ) that accommodates said coupling element ( 103 ), with provision for play in a circumferential direction. 
 
     
     
       7. The diaphragm chuck in accordance with  claim 3 ,
 wherein 
 the width of the coupling element ( 103 ) and the internal clearance of the recess ( 105 ,  105 ′) are dimensioned so that the coupling element ( 103 ) can be inserted into the recess ( 105 ,  105 ′) in a position turned through 90° in relation to an operating position. 
 
     
     
       8. The diaphragm chuck in accordance with  claim 7 ,
 wherein 
 a separation point of the contact piece ( 22 ) is sealed by a labyrinth seal ( 110 ) formed onto the end surfaces of at least one part ( 22   b ) of the contact piece ( 22 ). 
 
     
     
       9. The diaphragm chuck in accordance with  claim 1 ,
 wherein 
 each intermediate element ( 111 ) comprises an elastically deformable zone ( 112 ) integrated into the contact piece ( 22 ). 
 
     
     
       10. The diaphragm chuck in accordance with  claim 9 ,
 wherein 
 each elastically deformable zone ( 112 ) comprises an intermediate piece ( 113 ) in the form of a selected one of a pin and a plate, and said zones ( 112 ) are formed by recesses in the contact pieces ( 22 ). 
 
     
     
       11. The diaphragm chuck in accordance with  claim 1 ,
 wherein 
 the intermediate element ( 121 ) comprises a connecting pin ( 122 ) positioned in the parts ( 22   a ′,  22   b ′) of the contact piece ( 22 ) and arranged at a distance from one another in the area of a subdivision of the contact piece ( 22 ) and held in at least one part of the contact piece ( 22 ) with axial play. 
 
     
     
       12. The diaphragm chuck in accordance with  claim 11 ,
 wherein 
 said connecting pin is held on at least one end by a cross pin ( 113 ,  114 ) inserted in each of the parts of the contact piece, the cross pins ( 113 ,  114 ) engaging in one of lengthwise grooves ( 115 ,  116 ) in said connecting pin and directly in said connecting pin with axial play. 
 
     
     
       13. The diaphragm chuck in accordance with  claim 1 ,
 wherein 
 the intermediate element ( 131 ) comprises a threaded rod ( 132 ) with at least one end screwed into a threaded hole ( 113 ,  114 ) in a part of the contact piece ( 22 ) in an area of a subdivision of the contact piece. 
 
     
     
       14. The diaphragm chuck in accordance with  claim 13 , wherein the contact pieces ( 22 ) of said clamping jaws and the clamping heads ( 21 ), and at least the parts ( 22   a ′) of the contact pieces ( 22 ) formed directly onto these same, are arranged in the diaphragm ( 4 ) and said counterweights ( 8 ) with radial play.